Conveyor

ABSTRACT

A conveyor chain for conveyor cars and the like having a plurality of rollers for engagement with guide rails for the chain and a plurality of members carried by the chain having at least one substantially flat surface extending laterally of the chain adapted to be engaged by a chain driving member.

BACKGROUND AND SUMMARY OF THE INVENTION

This invention relates generally to conveyor chains for conveyorsystems, for example, for a system like that disclosed in the patent toCzarnecki et al, U.S. Pat. No. 3,435,780, issued Apr. 1, 1969, andassigned to the assignee of this application. As shown in the abovepatent, conveyor chains are conventionally driven by driving membersdisposed on opposite sides of the chain which engage the arcuatesurfaces of rollers carried by the chain. In some installations, forexample, in foundries where the conveyor assembly may carry heavy moldsbetween various levels of the foundry, very large driving forces arerequired to move the conveyor assembly. With large driving forces, thearcuate surfaces of the rollers develop laterally-outward forces tendingto spread the driving members. In addition to the above undesirabletendency, the force of the driving members against the rollers isgenerally detrimental to the life of the bearings for the rollers. As astill additional disadvantage, the rollers must be sufficiently large indiameter to extend laterally outwardly of the driving members to providea substantial surface component which is crosswise of the chain toefficiently receive the force of the driving members. As a result, therollers tend to engage the guides for the chain during chording of thechain when a curved path of relatively small radius is negotiated.

The present invention solves the above problems by providing a laterallyextending driven member or block on the chain which has flat surfacesdisposed crosswise of the chain for engagement by the driving members ofthe drive means. Accordingly, substantially no laterally-outward forcesare developed, and consequently, there is no tendency to spread thedriving members. Furthermore, since the crosswise flat surfaces of thedriven members may readily extend to the lateral extremities of thedriven members, the driven members may be constructed with a lesserextension laterally of the chain than rollers used for this purpose soas to avoid engagement of the driven members with the guide rails of thechain during chording of the chain as it negotiates a curved path.Additionally, the bearings for the rollers no longer receive the drivingforce thereby providing increased roller bearing life. Preferably, thedriven members are pivotally mounted to the chain so as to accommodateany angular misalignment between the driving members and driven members.Also, preferably, the driven members are mounted intermediate the pivotfor the chain so that they may be removed for replacement or repairwithout dismantling of the chain.

In view of the above and the following detailed description of thepreferred embodiment of this invention, it will be appreciated that theimproved conveyor chain provided by this invention is a significantadvance in this art.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective illustration of a mold car driven by anexemplary conveyor chain construction according to this invention;

FIG. 2 is an end cross-sectional view of the mold car and conveyor chainconstruction shown in FIG. 1;

FIG. 3 is a top view illustrating the manner in which the conveyor chainconstruction of FIG. 1 negotiates a curved path;

FIG. 4 is a top view of a conveyor chain construction of FIG. 1 showingthe manner of engagement of the chain with driving dogs of a drive meansfor the conveyor chain; and

FIG. 5 is a side view, partially in section, illustrating the mold carand conveyor chain construction of FIG. 1 showing the manner ofengagement of the chain with driving dogs of a drive means for theconveyor chain.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In FIG. 1, an exemplary conveyor car and conveyor chain assembly isshown generally designated 10 which is suitable for use, for example, ina foundry for conveying molds to various molding operation locations.The assembly 10 may include a conveyor car generally indicated at 12 anda conveyor chain assembly generally indicated at 14. The conveyor cars12 may comprise a top 16 on which conveyable articles are carried, forexample, the molds for a molding operation. The car tops 16 are mountedon king pins 18 which are connected to the axles 20 by means ofT-connectors 22. The car top 16, in addition to being mounted on theking pins 18, is also supported by downwardly extending flanges 24 whichsupport the car top 16 on four bolster wheels 26. The bolster wheels 26are free wheeling on the axle 20 and there is normally relative movementbetween the bolster wheels 26 and the flanges 24 only when the conveyorcar 12 is negotiating turns. The conveyor car 12 moves along a pathtaken by the conveyor system by rolling on wheels 28 which are guidedalong a roadway or track for the conveyor car 12 consisting of a pair ofrails 30. A chain 32, .Iadd.comprising pivotally interconnected pairs oflinks is .Iaddend.guided along a path provided by a pair of.Iadd.vertical .Iaddend.rails 34, .Iadd.and .Iaddend.drives or propelsthe cars 12 along the path defined by the rails 30. The rails 30 may bemounted on a bed 36 while the rails 34 may be mounted on verticalextensions 38.

The T-connector 22 is removably secured to .Iadd.the conveyor chain 32at .Iaddend.a .[.pivotal.]. .Iadd.universal .Iaddend.joint 40.Iadd.which comprises a part .Iaddend.of the chain 32 .[.which.]..Iadd.and .Iaddend.provides for vertical articulation of the chain whenthe path defined by the rails 30 changes upwardly or downwardly..[.The.]. .Iadd.In the form of the invention here shown, a.Iaddend.universal joint 40 generally .[.connects vertically spacedpairs.]. .Iadd.is provided midway between the ends of each pair.Iaddend.of chain links.Iadd.. It will be observed that the two links ofeach pair are spaced vertically apart and are formed of two separateleft and right portions .Iaddend.42 and 44 .Iadd.of substantially equallength, as perhaps best shown in FIG. 5. In each instance, the left handportions 42 are welded or otherwise fixedly connected at the inner endsthereof to one end portion of the universal joints 40 and the right handportions 44 are similarly welded at the inner ends thereof to the otherend portion of the universal joints. At the outer ends thereof, the leftand right link portions 42 and 44 .Iaddend. .[.which pairs.]. arepivotally connected by pins 46 to adjacent .Iadd.similar and.Iaddend.complementary .[.pins.]. .Iadd.pairs .Iaddend.of links .[.42 or44.].. The pins 46 provide for horizontal articulation of the chain 32when the guide rails 30 bend leftwardly or rightwardly in the horizontalplane, .[.or.]. .Iadd.viz, in .Iaddend.a plane parallel to the car top16. The pins 46 also carry rotatably mounted rollers 48 which.Iadd.space the outer end portions of the upper and lower links of thechain 32 and .Iaddend.are preferably mounted by bearings 50 asillustrated in FIG. 5. In the general arrangement as shown, a roller 48is mounted intermediate each pair of adjacent conveyor cars 12 as wellas centrally of each conveyor car 12.

Rectangular blocks 52 are carried by the chain 32 between the.[.links.]. .Iadd.link portions .Iaddend.42 .[.and.]. .Iadd.adjacent toa universal joint 40 and between the universal joint and an adjacentroller 48. The drive blocks .Iadd.52 .Iaddend.extend laterally.[.thereof,.]. .Iadd.of the chain 32 .Iaddend.and are preferably mountedfor limited .[.rotation.]. .Iadd.pivotal movement .Iaddend.in ahorizontal plane as by pins 54 extending through the .[.links.]..Iadd.link portions .Iaddend.42 and the blocks 52. The blocks 52 aredisposed a predetermined distance .[.forward.]. .Iadd.forwardly.Iaddend.of the nearest roller 48 so as to accommodate an upward arcuatemovement of a pair of driving dogs or members 56 of a .Iadd.conventional.Iaddend.driving apparatus, only partially shown in FIG. 5. As can bebest seen in FIG. 4, .Iadd.each pair of driving dogs 56 straddle thechain 32, and each .Iaddend..[. the blocks.]. .Iadd.block .Iaddend.52.[.have.]. .Iadd.has .Iaddend.a pair of flat surfaces 58, .[.eachextending.]. .Iadd.which extend .Iaddend.laterally from .[.one side.]..Iadd.opposite sides .Iaddend.of the .Iadd.chain .Iaddend.links .[.42.].and .[.being.]. .Iadd.are .Iaddend. adapted to .Iadd.be engaged bycorrespondingly .Iaddend..[.engage a corresponding.]. flat .[.surface.]..Iadd.surfaces .Iaddend.on a driving dog 56. It will be appreciated that.Iadd.if the blocks are pivotally mounted on the pins 54 in thepreferred manner .Iaddend.any angular misalignment between the flatsurfaces .[.on.]. .Iadd.of .Iaddend.the dogs 56 and the driven blocks 52are accommodated by pivotal movement of the blocks 52 about .[.pivot.]..Iadd.pivots .Iaddend.54. Thus, the driving force provided by thedriving dogs 56 is transmitted to the chain 32 through the pivot pins54. The .[.rearward.]. .Iadd.rearwardly .Iaddend.facing surfaces .[.═.]..Iadd.51 .Iaddend.of the driving dogs 56 may be arcuate in cross sectionso as to be adapted to fully engage the arcuate surfaces of the nearestrearward roller 48 .[.upon.]. .Iadd.which functions also as a hold backdog to limit .Iaddend.coasting of the chain 32 after driving movement ofthe dogs 56 has ceased .[.to limit such coasting movement of the chain32.]. thereby facilitating relatively accurate positioning of the cars12. As can be best seen in FIG. 3, the blocks 52 extend laterally of thechain links 42 a distance less than the lateral extension of the rollers48 so as to prevent engagement of the blocks 52 with the rails 34 duringchording of the chain 32 as it negotiates a curved path. The blocks 52may have a lesser lateral extension than a roller used for this purposesince it provides a continuous crosswise surface to its lateralextremities while a roller used for this purpose has only a slightcrosswise surface component near its lateral extremities, andaccordingly, must be made correspondingly larger in diameter to providea suitable engaging surface for the driving members. In the generalarrangement of the conveyor as shown, each of the driven blocks 52 ispositioned intermediate a pair of rollers 48, and particularly, betweena roller 48 and a vertical articulation point 40.

As can be best seen in FIG. 5, the driving dogs 56 are.Iadd.conventionally .Iaddend.mounted on rolling carriages 62 which aredriven by a .Iadd.caterpillar .Iaddend.chain and motor assembly, forexample, as illustrated in the aforementioned patent to Czarnecki et al,U.S. Pat. No. 3,435,780.

In one of its intended uses, the cars 12 carry sand molds for a foundryoperation. To prevent any spilled sand from interfering with thebearings 50 and the rollers 48, a sand shield 64 is mounted intermediatethe cars as by pins or studs 66 extending from the chain links 42 and 44into receptacles in the sand shield 64 as shown. To accommodate therelative angular motion of the chain links 42 and 44 when the chain 32negotiates a curved path, the receptacle for one of the pins 66 may beslotted or elongated. The sand shield 64 preferably slopes laterally asshown to deflect the sand to the sides of the conveyor 10. It may alsohave fore and aft bevels or slopes, if desired.

In view of the above description of an exemplary conveyor system 10according to this invention, it will now be appreciated that anefficient driving engagement is provided between the drive dogs 56 andthe driven blocks 52. Moreover, the bearings 50 supporting the rollers48 are not carrying the driving forces, and therefore, are only forciblyloaded upon engagement of the rollers 48 with the guide rails 34 whennegotiating a curved path and occasionally when the rollers 48 engagethe guide rails 34 when the conveyor chain 32 is transversing a straightpath. Accordingly, the service .[.lie.]. .Iadd.life .Iaddend. of thebearings 50 is benefitted. In addition to the above advantages, thedriven blocks 52 may be easily removed for repair or replacement withoutdismantling the chain 32. It will be appreciated that this is asignificant advantage as the difference in elevation between thedifferent levels of a foundry may exert a force on the chain preventingconvenient assembly of the chain after dismantling.

While it will be apparent that the teachings herein are well calculatedto teach one skilled in the art the method of making the preferredembodiment of this invention, it will be appreciated that the inventionis susceptible to modification, variation and change without departingfrom the proper scope or meaning of the subjoined claims.

What is claimed is:
 1. In a conveyor chain assembly, a chain comprisingconnected pairs of spaced links, curved guide rails on opposite sides ofsaid chain, a plurality of rollers carried by pins connected betweensaid pairs of links and engageable with said guide rails as said chainpasses therethrough, whereby intermediate portions of said links betweensaid rollers will approach relatively closely to said guide rails, meansfor driving said conveyor chain assembly comprising a plurality ofblocks disposed between said pairs of links, each block having a pair ofplanar surfaces extending laterally outwardly in opposite directionsfrom said links, the extent of said surfaces being less than that whichwill cause engagement of said blocks with said guide rails during thechain assembly movement means for mounting said blocks for limitedrotation with respect to said links at intermediate portions thereofbetween said guide rollers, and a forked driving apparatus having a pairof driving dogs movable into position on opposite sides of a pair oflinks with lateral planar surfaces engageable with the lateral surfaceson said blocks.
 2. A conveyor chain assembly according to claim 1wherein said chain is pivotally connected for vertical articulationintermediate said rollers.
 3. A conveyor chain assembly according toclaim 1 further including a plurality of conveyor cars carried by saidchain.
 4. A conveyor chain assembly according to claim 3wherein saidconveyor cars are serially mounted to said chain with one of saidrollers intermediate adjacent ones of said conveyor cars.
 5. A conveyorchain assembly according to claim 4 including a shield mountedintermediate said cars adapted to deflect material falling from saidconveyor cars from said rollers intermediate said adjacent ones of saidconveyor cars. .Iadd.
 6. In a conveyor chain assembly, a chaincomprising connected pairs of spaced links; curved guide rails onopposite sides of said chain; a plurality of rollers carried by pinsconnecting said pairs of links and engageable with said guide rails assaid chain passes therebetween, whereby intermediate portions of saidlinks between said rollers approach relatively closely to said guiderails; and means for driving said chain comprising a plurality of blocksspaced along the length of said chain, each block being disposed betweenand attached to the links of a pair of said chain links and havingplanar surfaces extending laterally outwardly in opposite directionsfrom said links, said rollers following and being disposed adjacent tobut spaced from respective of said blocks, the lateral extent of saidsurfaces being less than that which will cause engagement of said blockswith said guide rails during operation of said chain assembly, and adriving apparatus having pairs of forked driving dogs movable intoposition on opposite sides of said chain, said dogs having lateralplanar surfaces engageable with the lateral surfaces of said blocks..Iaddend..Iadd.
 7. In a conveyor chain assembly, a chain adapted to movealong a predetermined path and comprising pairs of spaced links arrangedin end-to-end relation; means including pins interconnecting said pairsof links; curved guide rails alongside said chain at curved sections ofsaid predetermined path; antifriction rollers mounted on said pinsadapted to ride on said guide rails as said chain negotiates said curvedsections in use, portions of said links between said rollers approachingrelatively closely to said guide rails due to chording of the links asthe rollers move on said guide rails; blocks connected to at leastcertain of said pairs of links, each of said blocks being disposed aheadof and adjacent to but spaced from a respective one of said rollers andsaid blocks having planar surfaces extending laterally outwardly inopposite directions from said links, the lateral extent of said planarsurfaces being less than that which will cause engagement of said blockswith said guide rails in the operation of said chain assembly; and adriving apparatus coactive with said chain to move the same under poweralong said predetermined path, said apparatus having pairs of drivingdogs, each pair of dogs disposed to straddle said chain behind one ofsaid blocks and being engageable with the planar surfaces of said block..Iaddend..Iadd.
 8. In a conveyor chain assembly, a chain comprising aplurality of links arranged in pairs and connected end-to-end by meansincluding pivots; rollers on said pivots; curved guide rails coactivewith said rollers to control the path of movement of said chain in use;intermediate portions of said links between said rollers approachingrelatively closely to said guide rails in use; and means for drivingsaid conveyor chain comprising a plurality of blocks spaced along thelength of said chain, each block being attached to links of said chainahead of and adjacent to but spaced from a respective one of saidrollers, said blocks having planar surfaces extending laterallyoutwardly in opposite directions from said links, the lateral extent ofsaid surfaces being less than that which will cause engagement of saidblocks with said guide rails during operation of said chain assembly;and a drive apparatus having pairs of driving dogs, each pair of dogsadapted in operation of said drive to straddle said chain between one ofsaid blocks and the adjacent roller and being provided with lateralplanar surfaces engageable during said operation with the planarsurfaces of said block, said dogs when in driving position against saidblocks being spaced from the adjacent rollers but operative to beengaged by said rollers to limit over-travel and coasting of said chainduring certain operating conditions of said conveyor chain assembly..Iaddend..Iadd.
 9. A conveyor chain assembly adapted to travel betweenguide rails at least certain portions of which are curved, said chainassembly comprising pairs of spaced links having overlapping endportions; pins interconnecting the overlapping end portions of saidlinks; rollers mounted for rotation on said pins extending laterally ofsaid links for rolling engagement with said guide rails and operative tohold the portions of said links between said rollers free fromengagement with said rails; means for driving said conveyor chaincomprising a plurality of blocks disposed between and connected to atleast certain of said links and having planar driving surfaces extendinglaterally outwardly in opposite directions from said links, said rollersfollowing and being disposed adjacent to but spaced from said blocks,the length of said blocks and the lateral extent of said drivingsurfaces being less than that which will cause engagement of said blockswith said guide rails during operation of said chain assembly; and aforked driving apparatus having pairs of driving dogs movable intoposition on opposite sides of said chain and engageable with the planardriving surface of said blocks. .Iaddend. .Iadd.
 10. In a chain conveyorof the type having an endless chain; means for guiding said chainthrough a predetermined path of travel including laterally spaced guiderails along curved sections of said path on opposite sides of said chainand rollers carried by and extending laterally from opposite sides ofsaid chain engageable with said guide rails; and a power drive for saidchain having a plurality of spaced forked driving elements arranged tostraddle said chain, the improvement comprising a plurality of blockscarried by said chain and having portions thereof extending laterally inopposite directions from said chain, said blocks being disposed ahead ofand adjacent to but spaced from respective of said rollers, said blocksbeing spaced along the chain for engagement by said forked drivingelements and said laterally extending portions having transverse planarsurfaces on which said elements seat, said rollers extending laterallyfrom the chain sufficiently farther than said blocks to hold the latterfree from engagement with said guide rails. .Iaddend..Iadd.
 11. Thecombination as set forth in claim 10 wherein said rollers defineholdback means engageable with the forked elements to limit coasting ofsaid chain under certain operating conditions of said conveyor..Iaddend..Iadd.
 12. In a chain conveyor of the type having an endlesschain; means for guiding said chain through a predetermined path oftravel having opposed, laterally spaced, vertical guide surfaces alongcurved sections of said path and rollers carried by and extendinglaterally from opposite sides of said chain engageable with said guidesurfaces; and a power drive for said chain having a plurality of spacedforked driving elements arranged to straddle said chain, the improvementcomprising a plurality of blocks carried by and having portions thereofextending laterally in opposite directions from said chain, said blocksbeing disposed ahead of and adjacent to but spaced from respective ofsaid rollers, said driving elements being operative to moveprogressively into position behind successive blocks for drivingengagement with the latter and said blocks having planar rear surfacesdisposed substantially transversely of said chain against which saidelements seat to drive the chain, said rollers extending laterally fromthe chain sufficiently farther than said blocks to hold the latter freefrom engagement with said guide surfaces, and said following rollersbeing engageable with said forked driving elements to limit over-traveland coasting of said chain. .Iaddend.